Method of attaching an electronic module power supply

ABSTRACT

Power may be supplied to an electronic module according to various techniques. In one general implementation, for example, a system for supplying power to an electronic module may include a printed circuit board, the electronic module, and a conductive foil. The board may include a number of contact locations on a first side, with at least one of the contact locations electrically coupled to a via to a second side of the board. The electronic module may be electrically coupled to the contact locations on the first side of the board and receive electrical power through the at least one contact location electrically coupled to a via. The foil may be adapted to convey electrical power for the electronic module and electrically coupled on the second side of circuit board to at least the via electrically coupled to a contact location that receives electrical power for the electronic module.

BACKGROUND

The present invention relates to electronic modules, and morespecifically to supplying electrical power to electronic modules.

Printed circuit boards provide a structure on which to integrate variouselectronic components. The integration may be both structural andelectrical. That is, a printed circuit board may provide a common baseby which to physically couple electronic components and provide a mannerin which to electrically couple two or more of them. Physical couplingmay, for example, take place through coupling electronic components tothe printed circuit board by pin sockets and/or soldering. Electricalcoupling between electronic components coupled to a printed circuitboard may, for example, take place through conductive traces on or inthe printed circuit board.

A printed circuit board may also include planes for providing commonelectrical coupling between components. The commons planes may, forexample, be used for power, ground, and signaling. For a printed circuitboard having electronic components that operate in different powerdomains, a number of planes may be included. Other solutions may involvethe use of bus bars to provide power for an electronic component.

BRIEF SUMMARY

In one general implementation, a system for supplying electrical powerto an electronic module may include a printed circuit board, anelectronic module, and a conductive foil. The printed circuit board mayinclude a number of contact locations on a first side, with at least oneof the contact locations electrically coupled to a via to a second sideof the printed circuit board. The electronic module may be electricallycoupled to the contact locations on the first side of the printedcircuit board and receive electrical power through the at least onecontact location electrically coupled to a via to a second side of theprinted circuit board. The conductive foil may be adapted to conveyelectrical power for the electronic module and electrically coupled onthe second side of the circuit board to at least the via that iselectrically coupled to a contact location that receives electricalpower for the electronic module.

In another general implementation, a system for supplying electricalpower to an electronic module may include a conductive foil. Theconductive foil may have a first side and a second side and be adaptedto convey electrical power for an electronic module. The conductive foilmay include electrical coupling locations on the first side thatcorrespond to a first set of printed circuit board vias and passagewaysfrom the first side to the second side that correspond to a second setof printed circuit boards vias.

The details and features of various implementations will be conveyed bythe following description, along with the drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a drawing illustrating an example system for supplying powerto an electronic module.

FIG. 2 is another drawing illustrating an example system for supplyingpower to an electronic module.

FIG. 3 is a drawing illustrating an example system for coupling aconductive foil to a printed circuit board.

FIG. 4 is a drawing illustrating an example printed circuit board forconveying electrical power from a conductive foil to an electronicmodule.

FIG. 5 is a drawing illustrating an example conductive foil that may beused to convey electrical power for an electronic module.

FIG. 6 is a drawing illustrating of an example insulator.

FIG. 7 is a flowchart illustrating an example process 700 for forming apower supply for an electronic module.

DETAILED DESCRIPTION

Electrical power may be supplied to a printed-circuit-board-mountedelectronic module through a variety of techniques. In certainimplementations, a conductive foil may convey electrical power on theside of a printed circuit board that is opposite the side on which anelectronic module is mounted. Thus, electrical power may be delivered toan electronic module without having to add additional power planes tothe printed circuit board, which can assist in reducing its thicknessand manufacturing complexity. Moreover, the conductive foil may be addedafter the printed circuit board is manufactured, which may be usefulwhen post-manufacturing design changes are required.

FIG. 1 illustrates an example system 100 for supplying power to anelectronic module. In general, system 100 includes a printed circuitboard 110, an electronic module 120, a voltage regulator 130, and aconductive foil 140.

Printed circuit board 110 may be any appropriate structure forstructurally mounting and electrically coupling electronic components,such as resistors, capacitors, inductors, processors, and transceivers.Printed circuit board 110 has two sides 112 a, 112 b with dimensionsthat are typically relatively large compared to the board's thicknessand may be composed of any appropriate material (e.g., fiberglass orFR-4). Printed circuit board 110 typically contains a variety ofelectrical conduits (e.g., traces, power planes, and ground planes) forelectrically coupling electronic components mounted thereto.

Electronic module 120 may be any type of powered electronic device. Forexample, electronic module 120 may be a processor (e.g., amicroprocessor, a microcontroller, or an application specific integratedcircuit) or a transceiver. Electronic module 120 may be electricallycoupled to printed circuit board 110 by any appropriate technique. Forexample, the electronic module may be coupled to a landing grid array(LGA) or ball grid array (BGA) on the printed circuit board. In theillustrated implementation, electronic module 120 is coupled to anelectrical interface 114. Electrical interface 114 may, for example, bean LGA socket or a BGA socket, with or without a downstop incorporated,into which the electronic module can plug.

Voltage regulator 130 is responsible for supplying electrical power forelectronic module 120. In the illustrated example, voltage regulator 130converts power from printed circuit board 110 to power for electronicmodule 120. For instance, the voltage regulator could convert a 5V poweron the printed circuit board to a 1V power for the electronic module.Voltage regulator 130 may be electrically coupled to printed circuitboard 110 by any appropriate technique. For example, the voltageregulator may be coupled to an LGA or a pin grid array (PGA) on theprinted circuit board. In the illustrated implementation, the voltageregulator is coupled to an electrical interface 116. Electricalinterface 116 may, for example, be an LGA or a PGA socket into which thevoltage regulator can plug.

Conductive foil 140 is responsible for conveying at least some of theelectrical power for electronic module 120 from voltage regulator 130.Conductive foil 140 may, for example, carry a relatively high DC currentfor electronic module 120. Conductive foil 140 has a first side 142 aand a second side 142 b, which typically have dimensions that aresubstantially larger than the thickness of the conductive foil.Conductive foil 140 may, for example, have a thickness between 60-500microns, which can vary based on application. Conductive foil 140 may becomposed of copper, gold, and/or any other appropriate conductivematerial.

Conductive foil 140 may be electrically coupled to voltage regulator 130by any appropriate technique. In this illustrated example, conductivefoil 140 is directly coupled to voltage regulator 130 by an attachmentmechanism (e.g., a screw). In other implementations, the coupling may,for instance, be made by a clamp.

Conductive foil 140 is also electrically coupled to printed circuitboard 110. As will be explained in more detail below, conductive foil140 may, for instance, be electrically coupled to one or more vias inthe printed circuit board that convey electricity to one or more contactlocations (e.g., grid pads) on first side 112 a of the printed circuitboard.

System 100 also includes an insulator 150, a conformal fill material160, a structural support member 170, and a heat sink 180. Insulator 150electrically insulates conductive foil 140 from other components ofsystem 100, including those used to physically couple the conductivefoil to printed circuit board 110. In certain implementations, insulator150 should be thin and flexible enough to allow the pressure ofconformal fill material 160 to mold the insulator and the conductivefoil to the contours of printed circuit board 110 with sufficient forceto make effective electrical couplings. Insulator 150 may, for example,be made of rubber, vinyl, or any other appropriate electricallyinsulating material.

Conformal fill material 160 deforms to spread pressure when compressedby structural support member 170. Conformal fill material 160 may, forexample, be made of any appropriate conformable material. For instance,the conformal fill material may be made of expanded Polypropylene (EPP)foam, which is readily deformable. EPP foam can also withstand extremelyhigh temperatures (130 degrees C.) and is highly durable.

In certain implementations, conformal fill material 160 may be adheredto insulator 150 or structural support member 170. Additionally,conductive foil 140 could actually be one manufactured piece thatincludes the conformal material, the insulator, and the conductive foillaminated together in such away that flexibility is maintained.

Structural support member 170 provides a relatively rigid structure formounting conductive foil 140, insulator 150, and conformal fill material160 to printed circuit board 110. Structural support member 170 isphysically coupled to printed circuit board 110 by mounting posts 190,which also couple to heat sink 180. Heat sink 180, which is mounted tothe top of electronic module 120 in this example, provides a way forelectronic module 120 to dissipate heat.

In the illustrated example, structural support member 170 compressesconductive foil 140, insulator 150, and conformal fill material 160between printed circuit board 110 and the structural support member asthe structural support member is mounted to posts 190, which also coupleheat sink 180 to printed circuit board 110. As the compression occurs,conformal fill material 160 deforms according to irregularities on thesurface of second side 112 b of printed circuit board 110. Theirregularities may, for example, be irregularities in the physicalstructure of side 112 b of the printed circuit board and/orirregularities due to components (e.g., traces) installed on side 112 b.The deformation of conformal fill material 160 deforms insulator 150 andconductive foil 140 so that conductive foil 140 may also conform to theirregularities of the printed circuit board surface to make electricalcouplings at the appropriate locations of printed circuit board 110.

System 100 additionally includes an insulator 152. Insulator 152 may beused to insulate other via ends in printed circuit board 110, which maynot be associated with electronic module 120, from conductive foil 140.

In one mode of operation, voltage regulator 130 receives electricalpower from printed circuit board 110. Printed circuit board 110 may, forinstance, contain one or more planes for conveying power to variouselectronic modules mounted on the printed circuit board, and the voltageregulator may be coupled to one of these power planes. Voltage regulator130 then converts the electrical power from the printed circuit board toan appropriate electrical power for electronic module 120. Voltageregulator 130 sends the electrical power through conductive foil 140 tothe vias in the printed circuit board that are coupled to contactlocations (e.g., grid pads) that receive electrical power for theelectronic module, which thus supplies operational power to theelectronic module. A return path to the voltage regulator 130 may, forinstance, be supplied by a ground plane in the printed circuit board.

Since conductive foil 140 may convey the majority of the current fromvoltage regulator 130 to electronic module 120, a large inductive loopmay be formed. In another mode of operation, voltage regulator 130 mayalso send a portion of the electrical power through a power plane ofprinted circuit board 110, which may be at ground or weaker. Thus,electronic module 120 may receive operational power from the voltageregulator through two paths. The path through conductive foil 140 mayhave a relatively high inductance and, hence, respond relatively slowlyto transients, and the path through the power plane may have arelatively low inductance and, hence, respond relatively quickly totransients. In certain implementations, the conductive foil can convey aDC current and the power plane can convey an AC current.

As the electronic module's power changes, power noise can be generated.Printed circuit board 110 may therefore include a frequency decoupler118 (e.g., a capacitor) for decoupling the power paths in this mode. Thedecoupling may, for example, occur at the middle frequencies.

System 100 has a variety of features. For example, system 100 maydeliver power to an electronic module without having to add additionalpower planes or ground planes to the printed circuit board, which canassist in reducing its thickness and manufacturing complexity,especially if the electronic module is localized. The delivered powermay, for instance, be incompatible with that handled by the printedcircuit board's existing power planes. Moreover, the delivered power maybe higher than what a power plane of the printed circuit board canhandle, especially when conductive foil 140 can be made relativelythick. As another example, various components of system 100 (e.g., theconductive foil, the insulator, and the conformal fill material) may beadded after the printed circuit board is manufactured. Thus, system 100may be useful when adding an unplanned electronic module to the printedcircuit board.

In other implementations, a system for supplying power to an electronicmodule may include fewer, additional, and/or a different arrangement ofcomponents. For example, the vias that electrically couple to theconductive foil may not convey electrical power directly through theprinted circuit board. For instance, the vias may send some or all ofthe electrical power through printed circuit board planes to other viasthat convey the electrical power to the electronic module or otherelectronic components. Thus, the electronic module does not have to bedirectly opposite the conductive foil. As another example, variouscomponents of the coupling system, including the structural supportmember, the insulator, and the conformal fill material may bemanufactured with surface contours that complement any systematicirregularities in any of the other elements, which may be the case wherethe wiring in the printed circuit board has different densities withinthe electronic module shadow and results in non-planar surfaces on theboard. As another example, various components (e.g., the secondinsulator, the frequency decoupler, and/or the conformal fill) may notbe used. Moreover the structural mounting member may be any structurecapable of fitting the conductive foil against the printed circuitboard. As an additional example, various layers may be added to theconductive foil assembly as needed.

FIG. 2 illustrates another example system 200 for supplying power to anelectronic module. Similar to system 100, system 200 includes a printedcircuit board 210, an electronic module 220, a voltage regulator 230,and a conductive foil 240. As can be seen in this example, however,printed circuit board 210 also has a power plane 212, a signal plane213, and a ground plane 214, which may generally be used for carryingelectricity between various components mounted to the printed circuitboard. In this example, for instance, signal plane 213 is used forconveying signals between components other than voltage regulator 230and electronic module 220.

Printed circuit board 210 also includes a number of vias 216, which aregenerally used for electrically coupling components on different levelsof the printed circuit board. Typically, a region of a circuit board hasa large number of vias, but only two have been shown here for eachregion to clarify the description. For example, via 216d couples voltageregulator 230 to power plane 212, which is coupled to electronic module220. Thus, voltage regulator 230 can deliver power to electronic module220 through power plane 212. Additionally, via 216 a couples electronicmodule 220 to ground plane 214, which is coupled to voltage regulator230. Thus, a return is provided between electronic module 220 andvoltage regulator 230. Conductive foil 240 is coupled to contactlocation 218 of via 216 b to also supply electrical power to electronicmodule 220. The return path for conductive foil may be provided byground plane 214.

Although FIG. 2 illustrates one example of a system for supplying powerto an electronic module, other power supply systems may include fewer,additional, and/or a different arrangement of elements. For example, aprinted circuit board may contain a variety of electronic componentscoupled thereto. Moreover, the printed circuit board may includemultiple power planes, signal planes, and ground planes, which may beused for electrically coupling various components on the printed circuitboard. Additionally, conductive foil 240 may have a system for couplingit to printed circuit board 210.

FIG. 3 illustrates an example system 300 for coupling a conductive foil320 to a printed circuit board 310. In this example, printed circuitboard 310 includes a number of vias 314 from first side 312 a of printedcircuit board to second side 312 b. Vias 314 convey electrical powerfrom contact locations 316 (e.g., pads) on second side 312 b to contactlocations 316 (e.g., pads) on first side 312 a of printed circuit board310. Note that the printed circuit board may also have additional viasthat convey electrical signals to other contact location between firstside 312 a and second side 312 b.

Conductive foil 320 includes dendrite groups 322 associated with eachcontact location 316. Dendrites are basically small protuberances fromthe conductive foil that aid in making contact with the contactlocations. For example, a dendrite may assist with piercing debris andoxides and/or provide wipe, which is a relative mechanical movementbetween mating contacts during assembly that aids in digging throughoxide layers and pushing debris out of the way, as the system is mated.In certain implementations, the conductive foil may also be plated withgold or other metallurgy at the contact locations with dendrites inorder to improve the interconnection.

System 300 also includes an insulator 330, a conformal fill material340, and a structural support member 350, which can used to ensureproper contact between conductive foil 320 and contact locations 316. Ascan be seen, second side 312 b of printed circuit board 310 hasirregularities in its surface, which have been exaggerated in thisexample to illustrate the actual operation. But as structural supportmember 350 compresses conformal fill material 340, the material deformsaccording to the shape of second side 312 b, especially if insulator 330and conductive foil 320 are readily deformable. And this deformationcauses conductive foil 320 to deform to a shape that corresponds tosecond side 312 b, which assists in making contact between dendritegroups 322 and contact locations 316.

FIG. 4 illustrates an example printed circuit board 400 for conveyingelectrical power from a conductive foil to an electronic module. Inparticular, FIG. 4 illustrates a second side 412 b of printed circuitboard 400, where a first side of the printed circuit board has one ormore electronic modules coupled thereto.

Printed circuit board 400 includes a set of contact locations 420 onsecond side 412 b, which are coupled to vias. Set 420 includes contactlocations 422, which are electrically coupled to vias that areelectrically coupled to power receiving contact locations located on thefirst side of the printed circuit board. Thus, electrical power may flowthrough contact locations 422 from a conductive foil. Set 420 alsoincludes contact locations 424, which may be electrically coupled tocontact locations at various locations on the printed circuit board.Contact locations 422, 424 may, for example, pad areas. If contactlocations 422, 424 are pads areas, contact locations 422 may encompassthe vias associated with the power domain, and contact locations 424 maybe small pads. Between contact locations 422 is a conductive fillmaterial 430, which can serve to distribute electrical power betweencontact locations 422. As can be seen, however, a clearance is providedbetween fill material 430 and contact locations 424. Contact locations422 may be plated with gold or other metallurgy to improve theinterconnection with the conductive foil.

Printed circuit board 400 also includes alignment holes 440 and mountingholes 450. Alignment holes 440 can assist in positioning a conductivefoil, along with its coupling element(s). In certain implementations,for example, the position of a conductive foil may need to be tightlycontrolled so that is only makes contact with the appropriate contactlocations in set 420. Alignment holes 440 may, for instance, have postsinserted therein to facilitate alignment of the conductive foil, aninsulator, and/or a conformal fill material. Such posts may be incontact with the conductive foil and may be non-conductive (e.g., formedfrom plastic or floating metal) or ohmically attached to the powerdomain, with a relatively high resistance, for instance.

Mounting holes 450 may be used for structurally mounting one or morecomponents (e.g., a heat sink or an electronic module) to the printedcircuit board. For example, mounting posts for a heat sink located onthe first side of printed circuit board 410 could extend throughmounting holes 450 and be secured on the second side of the printedcircuit board. Additionally, a conductive foil may be secured to theprinted circuit board by the mounting holes.

Printed circuit board 400 also includes via ends 460 for otherelectronic modules coupled to the first side of the circuit board. Inparticular implementations, these via ends may be covered by aninsulator to prevent a conductive foil supplying power through contactlocations 422 from coming into contact with these ends.

Other implementations may include fewer, additional, and/or a differentarrangement of elements. For example, certain implementations may notinclude alignment apertures. As another example, the contact locationsnot associated with the electronic module power domain may have amodified padstack in the allegro design that has an enhanced solder maskover the contact locations. This could be used instead of clearances orin conjunction with clearances to help assure that no shorting occurs.As a further example, some or all of the vias not associated with thepower domain for the electronic module may not extend completely throughthe printed circuit board. These vias could, for instance, be coupled tointernal planes with signals going to other vias and eventually to otherelectronic components. As an additional example, the conductive foil maymake contact with the conductive fill material at locations other thanthe contact locations to provide more electrical contact area betweenthe two.

FIG. 5 illustrates an example conductive foil 500 that may be used toconvey electrical power for an electronic module. Conductive foil 500includes a number of locations 510 at which electrical coupling may bemade with vias of a printed circuit board that convey electrical powerto an electronic module on the opposite side of the printed circuitboard. Electrical coupling may, for example, be made to pads of thevias. Locations 510 may specially coated (e.g., with gold) and includestructure (e.g., dendrites) to assist with making an electrical couplingwith the vias. Conductive foil 500 also includes a number of apertures520 that provide clearance around the printed circuit board vias, andany associated contact locations, that have signals, ground, and/orpower other than for the power domain for the electronic modulereceiving power through the vias of the printed circuit board.

Conductive foil 500 additionally includes alignment apertures 530 andmounting apertures 540. Alignment apertures 530 assist with ensuringproper positioning of conductive foil 500 with respect to the printedcircuit board to which it will be mounted, which can prevent shortsbetween the foil and ground, signal, and other power domains. Mountingapertures 540 are large enough to allow clearance around any mountingposts (e.g., for a structural support member) to ensure that no ohmicconnection is made.

FIG. 6 illustrates an example insulator 600. Insulator 600 includesalignment apertures 610 and mounting apertures 620. Alignment apertures610 assist with ensuring proper positioning of insulator 600 withrespect to the printed circuit board to which it will be mounted.Mounting apertures 620 are large enough to allow clearance aroundmounting posts (e.g., for a structural support member). Note that aconformal fill material may be patterned similar to the insulator.

FIG. 7 illustrates an example process 700 for forming a power supply foran electronic module. Process 700 may, for example, be used to makesystem 100.

Process 700 calls for positioning a first side of a conductive foil nextto a printed circuit board such that an electrical coupling is made withvias that are electrically coupled to power receiving contact locationson an opposite side of circuit board (operation 704). The positioningmay, for example, be facilitated by aligning apertures in the conductivefoil with alignment posts in the printed circuit board. Additionally,the conductive foil may have mounting apertures therein, and these maybe aligned with mounting posts that extend from or through the printedcircuit board to aid in the positioning of the conductive foil.

Process 700 also calls for positioning a first side of an insulator nextto a second side of the conductive foil (operation 708). The positioningmay, for example, be facilitated by aligning apertures in the insulatorwith alignment posts in the printed circuit board. Additionally, theinsulator may have mounting apertures therein, and these may be alignedwith mounting posts that extend from or through the printed circuitboard to aid in the positioning of the insulator.

Process 700 additionally calls for positioning a first side of aconformal fill material next to a second side of the insulator(operation 712). The positioning may, for example, be facilitated byaligning apertures in the conformal fill material with alignment postsin the printed circuit board. Additionally, the conformal fill materialmay have mounting apertures therein, and these may be aligned withmounting posts that extend from or through the printed circuit board toaid in the positioning of the fill material.

Process 700 further calls for positioning a structural support membernext to a second side of the conformal fill material (operation 716).The positioning may, for example, be facilitated by aligning mountingapertures in the structural support member with mounting posts thatextend from or through the printed circuit board.

Process 700 also calls for coupling the structural support member to theprinted circuit board such that the conformal fill material compressesthe conductive foil against the printed circuit board (operation 720).The coupling may, for example, be accomplished by coupling thestructural support member to mounting posts that extend from or throughthe printed circuit board.

Process 700 further calls for coupling the conductive foil to a voltageregulator (operation 724). The voltage regulator may, for example,convert power from the printed circuit board to power for the electronicmodule.

Although process 700 illustrates one example process for forming a powersupply for an electronic module, other processes for forming a powersupply may include fewer, additional, and or a different arrangement ofoperations. For example, a process may not include positioning theinsulator next to the conductive foil and/or the conformal fill materialnext to the insulator, as two of more of these may be manufacturedtogether as one piece. Moreover, the insulator and/or the conformal fillmaterial may be positioned relative to the conductive foil before theconductive foil is positioned next to the printed circuit board.Additionally, the coupling to the voltage regulator may be performed atvarious points in a process.

The terminology used herein is for the purpose of describing particularimplementations only and is not intended to be limiting. As used herein,the singular form “a”, “an”, and “the” are intended to include theplural forms as well, unless the context clearly indicates otherwise. Itwill be further understood that the terms “comprises” and/or“comprising,” when used in the this specification, specify the presenceof stated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups therefore.

The corresponding structure, materials, acts, and equivalents of allmeans or steps plus function elements in the claims below are intendedto include any structure, material, or act for performing the functionin combination with other claimed elements as specifically claimed. Thedescription of the present implementations has been presented forpurposes of illustration and description, but is not intended to beexhaustive or limited to the implementations in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of thedisclosure. The implementations were chosen and described in order toexplain the principles of the disclosure and the practical applicationand to enable others or ordinary skill in the art to understand thedisclosure for various implementations with various modifications as aresuited to the particular use contemplated.

A number of implementations have been described for supplying power toan electronic module, and several others have been mentioned orsuggested. Moreover, those skilled in the art will readily recognizethat a variety of additions, deletions, modifications, and substitutionsmay be made to these implementations while still supplying power to anelectronic module. Thus, the scope of the protected subject mattershould be judged based on the following claims, which may capture one ormore concepts of one or more implementations.

The invention claimed is:
 1. A method comprising: positioning a firstside of a thin, deformable conductive foil against a first side of aprinted circuit board such that an electrical coupling is made with viasthat are electrically coupled to printed circuit board contact locationson an the opposite side of the printed circuit board; positioning afirst side of a thin, deformable insulator onto a second side of theconductive foil; positioning a thin, conformal fill material onto a sideof the insulator opposite the conductive foil; positioning a structuralsupport member located on a side of the fill material opposite theinsulator; and compressing the conductive foil, the insulator, and thefill material between the support member and the printed circuit boardsuch that the fill material deforms the conductive foil according toirregularities in the first side of the printed circuit board.
 2. Themethod of claim 1, wherein positioning the first side of the thin,deformable the conductive foil against the first side of the printedcircuit board comprises positioning the first side of the conductivefoil such that electrical coupling is not made with vias notelectrically coupled to power conveying contact locations on theopposite side of the printed circuit board.
 3. The method of claim 1,further comprising coupling the conductive foil to a voltage regulatoradapted to convert electrical power from a printed circuit board toelectrical power for an electronic module and convey the electricalpower through the conductive foil.